Method for manufacturing OLED device and OLED device manufactured therewith

ABSTRACT

The present invention provides a method for manufacturing an OLED device and an OLED device manufactured therewith. The method for manufacturing an OLED device includes: (1) providing a substrate and forming, in sequence, an anode and a hole transporting layer on the substrate; (2) forming an emissive layer on the hole transporting layer through a solution film casting process, wherein the emissive layer comprises a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel, of which at least one sub-pixel is formed of a quantum dot and at least one sub-pixel is formed of an organic light-emitting material; (3) forming, in sequence, an electron transporting layer and a cathode on the emissive layer; and (4) providing a package cover plate, which is set above the cathode, wherein the substrate and the package cover plate are bonded together by sealing enclosing resin to complete packaging of the OLED device. Since each sub-pixel of the emissive layer is formed through a solution film casting process, the manufacture of the OLED device requires no use of a fine metal mask so that the manufacturing cost is low, the utilization rate of material is high, and the yield rate is good.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of displaying technology, andin particular to a method for manufacturing an OLED device and an OLEDdevice manufactured therewith.

2. the Related Arts

An OLED (Organic Light-Emitting Diode) is a flat panel displayingtechnique of extremely prosperous future and it shows excellentdisplaying performance and also possesses various advantages, such asbeing self-luminous, simple structure, being ultra-thin, fast response,wide view angle, low power consumption, and being capable of achievingflexible displaying and is thus regarded as a “dream display”. Inaddition, the investment of manufacturing installation is far less thanthat of liquid crystal displays so that it has attracted the attentionof major display manufacturers and becomes the mainstream of thethird-generation display devices of the field of displaying technology.

Semiconductor nanocrystals (NCs) are semiconductor nanocrystals having asize of 1-100 nm. Since the semiconductor nanocrystals has a sizesmaller than exciton Bohn radii of other materials, show a strongquantum confinement effect, and exhibit new material properties, theyare also referred to as quantum dots (QDs).

Being excited by external energies (such as photoluminescence,electroluminescence, and cathodoluminescence), an electron leaps fromthe ground state to an excited state. Electrons and holes, when stayingin the excited state, may form excitons. The electrons and the holesrecombine and eventually relax back to the ground state. Excessiveenergy may be released through the process of recombination andrelaxation and there could be radiative recombination that gives offphotons.

Quantum dots light-emitting diodes (QD-LEDs) have very important valuefor commercial applications and have attracted strong intentions forresearch and development for the recent decade. In fact, compared toorganic light-emitting diodes (OLEDs), QD-LEDs have various advantages.(1) The light emitting from quantum dot has a line width between 20-30nm and compared to that of the light emitting from OELDs that is greaterthan 50 nm, FWHM (Full Width as Half Maximum) is relatively narrow,providing a key factor for achieving color purity of an image. (2)Inorganic materials have better thermal stability than organicmaterials. When a device is in a condition of high brightness or highcurrent density, Joule heat is a major cause for deterioration of thedevice. Due to the excellent thermal stability, an inorganic materialbased device would show an extended lifespan. (3) The organic materialsused for the three primary colors of red, green, and blue are ofdifferent lifespan and the color displayed by OLEDs would vary withtime. However, QDs can be formed of the same material to show differentsizes and emission of light with different colors can be achievedthrough the quantum confinement effect. The same material exhibits thesame deterioration rate. (4) QD-LEDs can achieve emission of infraredlight, while the wavelength of the emitting light of organic material isgenerally less than 1 micrometer. (5) Quantum dots are not subjected toconstraint imposed by spin statistics and the external quantumefficiency (EQE) may possibly reach 100%.

On the other hand, the evaporation process of OLED devices requires theuse of a fine metal mask (FFM). The process is expensive and has a lowutilization rate of material and poor yield rate. Thus, it is desired tohave a novel OLED device that has a simple manufacturing process, a highutilization rate of material, and a good yield rate.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method formanufacturing an OLED device and an OLED device manufactured therewith,which has an emissive layer of which each type of sub-pixel is madethrough solution film casting, wherein at least one type of sub-pixel ismade of an organic light-emitting material, where the manufacturingprocess of the OLED device requires no use of a fine metal mask so thatthe manufacturing cost is low, the utilization rate of material is high,and the yield rate is good.

To achieve the above object, the present invention provides a method formanufacturing an organic light-emitting diode (OLED) device, whichcomprises:

(1) providing a substrate and forming, in sequence, an anode and a holetransporting layer on the substrate;

(2) forming an emissive layer on the hole transporting layer through asolution film casting process, wherein the emissive layer comprises ared sub-pixel, a green sub-pixel, a blue sub-pixel, and a whitesub-pixel, of which at least one sub-pixel is formed of a quantum dotand at least one sub-pixel is formed of an organic light-emittingmaterial;

(3) forming, in sequence, an electron transporting layer and a cathodeon the emissive layer; and

(4) providing a package cover plate, which is set above the cathode,wherein the substrate and the package cover plate (2) are bondedtogether by sealing enclosing resin to complete packaging of the OLEDdevice.

The anode, the hole transporting layer, the electron transporting layer,and the cathode are each formed through a vacuum thermal evaporationprocess. The electron transporting layer is formed oftris-(8-hydroxyquinolinato)aluminum and the hole transporting layer isformed of poly(triphenylamine) or poly(ethylenedioxythiophene).

The substrate comprises a thin-film transistor (TFT) substrate. Thesubstrate and the package cover plate are formed of glass or a flexiblematerial. At least one of the substrate and the package cover plate islight transmittable.

In step (2), at least one of the sub-pixels is formed of a quantum dotand if the red sub-pixel is formed of a quantum dot, then the redsub-pixel is made by mixing an organic host material with a red quantumdot and a solvent, coating and volatizing to remove the solvent; if thegreen sub-pixel is formed of a quantum dot, then the green sub-pixel ismade by mixing an organic host material with a green quantum dot and asolvent, coating and volatizing to remove the solvent; if the bluesub-pixel is formed of a quantum dot, then the blue sub-pixel is made bymixing an organic host material with a blue quantum dot and a solvent,coating and volatizing to remove the solvent; and if the white sub-pixelis formed of a quantum dot, then the white sub-pixel is made by mixingan organic host material with a white quantum dot and a solvent, coatingand volatizing to remove the solvent or is alternatively made by mixingan organic host material with a combination of a red quantum dot, agreen quantum dot, and a blue quantum dot and a solvent, coating andvolatizing to remove the solvent; the blue quantum dot comprises ZnCdS,CdSe/ZnS or nanometer SiN₄, the green quantum dot comprising CdSe/ZnS orZnSe:Cu²⁺, the red quantum dot comprising CdSe/CdS/ZnS, the whitequantum dot comprising CdSe, Cds, CdTe, CdMnS, ZnSe, or ZnMnSe; theorganic host material comprises4,4′,4″-tri(carbazol-9-yl)-triphenylamine or2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine; and the solvent comprisesmethanol, ethanol, chlorobenzene, or chloroform.

In step (2), at least one of the sub-pixels is formed of a quantum dotand if the red sub-pixel is formed of a quantum dot, then the redsub-pixel is made by mixing a red quantum dot with a surface coatingagent and a solvent, coating and volatizing to remove the solvent; ifthe green sub-pixel is formed of a quantum dot, then the green sub-pixelis made by mixing a green quantum dot with a surface coating agent and asolvent, coating and volatizing to remove the solvent; if the bluesub-pixel is formed of a quantum dot, then the blue sub-pixel is made bymixing a blue quantum dot with a surface coating agent and a solvent,coating and volatizing to remove the solvent; and if the white sub-pixelis formed of a quantum dot, then the white sub-pixel is made by mixing awhite quantum dot with a surface coating agent and a solvent, coatingand volatizing to remove the solvent or is alternatively made by mixinga combination of a red quantum dot, a green quantum dot, and a bluequantum dot with a surface coating agent and a solvent, coating andvolatizing to remove the solvent; the surface coating agent comprisesstearic acid, trioctylphosphine oxide, or poly(methyl methacrylate); thesolvent comprises methanol, ethanol, water, chlorobenzene, orchloroform; and the blue quantum dot comprises ZnCdS, CdSe/ZnS ornanometer SiN₄, the green quantum dot comprising CdSe/ZnS or ZnSe:Cu²⁺,the red quantum dot comprising CdSe/CdS/ZnS, the white quantum dotcomprising CdSe, Cds, CdTe, CdMnS, ZnSe, or ZnMnSe.

In step (2), the at least one of the sub-pixels being formed of aquantum dot is that the blue sub-pixel is formed of a quantum dot.

In step (2), at least one of the sub-pixels is formed of an organiclight-emitting material and if the red sub-pixel is formed of an organiclight-emitting material, then the red sub-pixel is made by mixing anorganic host material with a red light emissive material and a solvent,coating and volatizing to remove the solvent; if the green sub-pixel isformed of an organic light-emitting material, then the green sub-pixelis made by mixing an organic host material with a green light emissivematerial and a solvent, coating and volatizing to remove the solvent; ifthe blue sub-pixel is formed of an organic light-emitting material, thenthe blue sub-pixel is made by mixing an organic host material with ablue light emissive material and a solvent, coating and volatizing toremove the solvent; and if the white sub-pixel is formed of an organiclight-emitting material, then the white sub-pixel is made by mixing anorganic host material with a red light emissive material, a green lightemissive material, a blue light emissive material and a solvent, coatingand volatizing to remove the solvent; the blue light emissive layercomprises 9,10-di(beta-naphthyl)anthracene, the green light emissivelayer comprising tris(2-phenylpyridine)iridium, the red light emissivelayer comprising 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran; the organic host material comprises4,4′,4″-tri(carbazol-9-yl)-triphenylamine or2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine; and the solvent comprisesmethanol, ethanol, chlorobenzene, or chloroform.

In step (2), the at least one of the sub-pixels being formed of anorganic light-emitting material is that the red sub-pixel, the greensub-pixel, and the white sub-pixel are formed of organic light-emittingmaterials.

The present invention also provides an OLED device manufactured with themethod claimed in Claim 1, which comprises a substrate, an anode formedon the substrate, a hole transporting layer formed on the anode, anemissive layer formed on the hole transporting layer, an electrontransporting layer formed on the emissive layer, a cathode formed on theelectron transporting layer, a package cover plate arranged above thecathode, and sealing enclosing resin arranged between the substrate andthe package cover plate to bond the substrate and the package coverplate together. The emissive layer comprises a red sub-pixel, a greensub-pixel, a blue sub-pixel, and a white sub-pixel. Each of thesub-pixels is formed through a solution film casting process. At leastone of the sub-pixels is made of a quantum dot and at least one of thesub-pixels is made of an organic light-emitting material.

The blue sub-pixel is formed of a quantum dot and the red sub-pixel, thegreen sub-pixel, and the white sub-pixel are formed of organiclight-emitting materials.

The efficacy of the present invention is that the present inventionprovides a method for manufacturing an OLED device, wherein each ofsub-pixels of an emissive layer is formed through a solution filmcasting process and an anode, a hole transporting layer, an electrontransporting layer, and a cathode are formed through vacuum thermalevaporation processes, so that the method for manufacturing the OLEDdevice requires no use of a fine metal mask thereby making themanufacturing cost incurring with the manufacturing method low, theutilization rate of material high, and the yield rate good; and with atleast one sub-pixel of the emissive layer being formed of a quantum dotand at least one sub-pixel being formed of an organic light-emittingmaterial, the manufacturing method according to the present invention,when compared with a manufacturing method where all sub-pixels areformed of quantum dots, has a relatively low manufacturing cost and,when compared with a manufacturing method where all sub-pixels areformed of organic light-emitting materials, provides an OLED devicehaving a better performance. An OLED device manufactured with thepresent invention combines the advantages of a QD-OLED and asolution-film-cast OLED so as to possesses excellent performance,allowing for application to flat panel displays, televisions, and otherfields of displaying.

BRIEF DESCRIPTION OF THE DRAWINGS

The technical solution, as well as other beneficial advantages, of thepresent invention will become apparent from the following detaileddescription of an embodiment of the present invention, with reference tothe attached drawings.

In the drawings:

FIG. 1 is a flow chart illustrating a method for manufacturing an OLED(Organic Light-Emitting Diode) device according to the presentinvention;

FIG. 2 is a schematic view illustrating a structure of the OLED deviceaccording to the present invention;

FIG. 3 is a schematic plan view illustrating an arrangement of pixels ofthe OLED device according to the present invention;

FIG. 4 is a schematic view illustrating an application of thearrangement of pixels shown in FIG. 3 in a display panel;

FIG. 5 is a schematic view illustrating a thin-film transistor (TFT)drive circuit of the arrangement of pixels shown in FIG. 3

FIG. 6 is a schematic plan view illustrating another arrangement ofpixels of the OLED device according to the present invention; and

FIG. 7 is a schematic view illustrating an application of thearrangement of pixels shown in FIG. 6 in a display panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

To further expound the technical solution adopted in the presentinvention and the advantages thereof, a detailed description is given toa preferred embodiment of the present invention and the attacheddrawings.

Referring to FIG. 1, the present invention provides a method formanufacturing an organic light-emitting diode (OLED) device, whichcomprises:

Step 1: providing a and forming, in sequence, an anode 21 and a holetransporting layer 22 on the substrate 1.

Step 2: forming an emissive layer 23 on the hole transporting layer 22through a solution film casting process, wherein the emissive layer 23comprises a red sub-pixel 231, a green sub-pixel 232, a blue sub-pixel233, and a white sub-pixel 234, of which at least one sub-pixel isformed of a quantum dot and at least one sub-pixel is formed of anorganic light-emitting material.

Step 3: forming, in sequence, an electron transporting layer 24 and acathode 25 on the emissive layer 23.

Step 4: providing a package cover plate 2, which is set above thecathode 25, wherein the substrate 1 and the package cover plate 2 arebonded together by sealing enclosing resin 3 to complete packaging ofthe OLED device.

In Step 2, at least one of the sub-pixels is formed of a quantum dot. Ifthe red sub-pixel 231 is formed of a quantum dot, then the red sub-pixel231 can be made by mixing an organic host material with a red quantumdot and a solvent, coating and volatizing to remove the solvent; if thegreen sub-pixel 232 is formed of a quantum dot, then the green sub-pixel232 can be made by mixing an organic host material with a green quantumdot and a solvent, coating and volatizing to remove the solvent; if theblue sub-pixel 233 is formed of a quantum dot, then the blue sub-pixel233 can be made by mixing an organic host material with a blue quantumdot and a solvent, coating and volatizing to remove the solvent; and ifthe white sub-pixel 234 is formed of a quantum dot, then the whitesub-pixel 234 can be made by mixing an organic host material with awhite quantum dot and a solvent, coating and volatizing to remove thesolvent or can alternatively be made by mixing an organic host materialwith a combination of a red quantum dot, a green quantum dot, and a bluequantum dot and a solvent, coating and volatizing to remove the solvent.

Wherein, the organic host material comprises TCTA(4,4′,4″-tri(carbazol-9-yl)-triphenylamine) or TRZ(2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine).

The compound TCTA (4,4′,4″-tri(carbazol-9-yl)-triphenylamine) has astructural formula as follows:

The compound TRZ (2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine) has astructural formula as follows:

The solvent may comprise methanol, ethanol, chlorobenzene, orchloroform.

In Step 2, at least one of the sub-pixels is formed of a quantum dot. Ifthe red sub-pixel 231 is formed of a quantum dot, then the red sub-pixel231 can be made by mixing a red quantum dot with a surface coating agentand a solvent, coating and volatizing to remove the solvent; if thegreen sub-pixel 232 is formed of a quantum dot, then the green sub-pixel232 can be made by mixing a green quantum dot with a surface coatingagent and a solvent, coating and volatizing to remove the solvent; ifthe blue sub-pixel 233 is formed of a quantum dot, then the bluesub-pixel 233 can be made by mixing a blue quantum dot with a surfacecoating agent and a solvent, coating and volatizing to remove thesolvent; and if the white sub-pixel 234 is formed of a quantum dot, thenthe white sub-pixel 234 can be made by mixing a white quantum dot with asurface coating agent and a solvent, coating and volatizing to removethe solvent or can alternatively be made by mixing a combination of ared quantum dot, a green quantum dot, and a blue quantum dot with asurface coating agent and a solvent, coating and volatizing to removethe solvent.

Wherein, the blue quantum dot may comprise ZnCdS, CdSe/ZnS or nanometerSiN₄. The green quantum dot may comprise CdSe/ZnS or ZnSe:Cu²⁺. The redquantum dot may comprise CdSe/CdS/ZnS. The white quantum dot maycomprise a quantum dot of Groups II-VI, such as CdSe, Cds, CdTe, CdMnS,ZnSe, or ZnMnSe.

The surface coating agent may comprise a stearic acid, trioctylphosphineoxide, or poly(methyl methacrylate).

The solvent may comprise methanol, ethanol, water, chlorobenzene, orchloroform.

Preferably, in Step 2, the at least one of the sub-pixels being formedof a quantum dot is that the blue sub-pixel 233 is formed of a quantumdot.

In the above-described method of using a quantum dot to form asub-pixel, the organic host material and the surface coating agentprovide a common effect that is to prevent aggregation and oxidizationof the quantum dot. Since a quantum dot is a nanometer particle, whichis a zero-dimensional material, and has great surface activity, it iseasy to aggregate so as to lead to oxidization and quenching offluorescence.

In Step 2, at least one of the sub-pixels is formed of an organiclight-emitting material. If the red sub-pixel 231 is formed of anorganic light-emitting material, then the red sub-pixel 231 can be madeby mixing an organic host material with a red light emissive materialand a solvent, coating and volatizing to remove the solvent; if thegreen sub-pixel 232 is formed of an organic light-emitting material,then the green sub-pixel 232 can be made by mixing an organic hostmaterial with a green light emissive material and a solvent, coating andvolatizing to remove the solvent; if the blue sub-pixel 233 is formed ofan organic light-emitting material, then the blue sub-pixel 233 can bemade by mixing an organic host material with a blue light emissivematerial and a solvent, coating and volatizing to remove the solvent;and if the white sub-pixel 234 is formed of an organic light-emittingmaterial, then the white sub-pixel 234 can be made by mixing an organichost material with a red light emissive material, a green light emissivematerial, a blue light emissive material and a solvent, coating andvolatizing to remove the solvent.

Wherein, the organic host material may comprise TCTA(4,4′,4″-tri(carbazol-9-yl)-triphenylamine) or TRZ(2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine) and the solvent maycomprise methanol, ethanol, water, chlorobenzene, or chloroform.

The blue light emissive material may comprise9,10-di(beta-naphthyl)anthracene (ADN), which has a structural formulaas follows:

The green light emissive material may comprisetris(2-phenylpyridine)iridium (Ir(ppy)₃), which has a structural formulaas follows:

The red light emissive material may comprise4-(dicyanomethylene)-2-methyl-6-(4-di methylaminostyryl)-4H-pyran (DCM),which has a structural formula as follows:

Preferably, in Step 2, the at least one of the sub-pixels being formedof an organic light-emitting material is that the red sub-pixel 231, thegreen sub-pixel 232, and the white sub-pixel 234 are formed of organiclight-emitting materials.

The substrate 1 can be a thin-film transistor (TFT) substrate. Thesubstrate 1 and the package cover plate 2 are formed of glass or aflexible material. At least one of the substrate 1 and the package coverplate 2 is light-transmittable. Preferably, the substrate 1 and thepackage cover plate 2 are both made of glass sheets. The substrate 1 andthe package cover plate 2 are bonded together by means of the sealingenclosing resin 3 to prevent invasion of external moisture and oxygen soas to seal and protect internal electronic components.

The anode 21, the hole transporting layer 22, the electron transportinglayer 24, and the cathode 25 are each formed through a vacuum thermalevaporation process so that no fine metal mask (FMM) is needed.Preferably, the electron transporting layer 24 is formed oftris-(8-hydroxyquinolinato)aluminum (Alq3) and the hole transportinglayer 22 is formed of poly(triphenylamine) (poly-TPD) orpoly(ethylenedioxythiophene) (PEDOT).

Referring to FIG. 2, based on the manufacturing method described above,the present invention further provides an OLED device, which comprises asubstrate 1, an anode 21 formed on the substrate 1, a hole transportinglayer 22 formed on the anode 21, an emissive layer 23 formed on the holetransporting layer 22, an electron transporting layer 24 formed on theemissive layer 23, a cathode 25 formed on the electron transportinglayer 24, a package cover plate 2 arranged above the cathode 25, andsealing enclosing resin 3 arranged between the substrate 1 and thepackage cover plate 2 to bond the substrate 1 and the package coverplate 2 together.

The emissive layer 23 comprises a red sub-pixel 231, a green sub-pixel232, a blue sub-pixel 233, and a white sub-pixel 234, wherein each ofthe sub-pixels is formed through a solution film casting process and atleast one of the sub-pixels is made of a quantum dot and at least one ofthe sub-pixels is made of an organic light-emitting material.Preferably, the blue sub-pixel 233 is made of a quantum dot.

Preferably, the blue sub-pixel 233 is made of a quantum dot and the redsub-pixel 231, the green sub-pixel 232, and the white sub-pixel 234 aremade of organic light-emitting materials.

For at least one of the sub-pixels being formed of a quantum dot, if thered sub-pixel 231 is formed of a quantum dot, then the red sub-pixel 231can be made by mixing a red quantum dot with a surface coating agent anda solvent, coating and volatizing to remove the solvent; if the greensub-pixel 232 is formed of a quantum dot, then the green sub-pixel 232can be made by mixing a green quantum dot with a surface coating agentand a solvent, coating and volatizing to remove the solvent; if the bluesub-pixel 233 is formed of a quantum dot, then the blue sub-pixel 233can be made by mixing a blue quantum dot with a surface coating agentand a solvent, coating and volatizing to remove the solvent; and if thewhite sub-pixel 234 is formed of a quantum dot, then the white sub-pixel234 can be made by mixing a white quantum dot with a surface coatingagent and a solvent, coating and volatizing to remove the solvent or canalternatively be made by mixing a combination of a red quantum dot, agreen quantum dot, and a blue quantum dot with a surface coating agentand a solvent, coating and volatizing to remove the solvent.

Wherein, the organic host material comprises TCTA(4,4′,4″-tri(carbazol-9-yl)-triphenylamine) or TRZ(2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine).

The compound TCTA (4,4′,4″-tri(carbazol-9-yl)-triphenylamine) has astructural formula as follows:

The compound TRZ (2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine) has astructural formula as follows:

The solvent may comprise methanol, ethanol, chlorobenzene, orchloroform.

For at least one of the sub-pixels being formed of a quantum dot, if thered sub-pixel 231 is formed of a quantum dot, then the red sub-pixel 231can be made by mixing a red quantum dot with a surface coating agent anda solvent, coating and volatizing to remove the solvent; if the greensub-pixel 232 is formed of a quantum dot, then the green sub-pixel 232can be made by mixing a green quantum dot with a surface coating agentand a solvent, coating and volatizing to remove the solvent; if the bluesub-pixel 233 is formed of a quantum dot, then the blue sub-pixel 233can be made by mixing a blue quantum dot with a surface coating agentand a solvent, coating and volatizing to remove the solvent; and if thewhite sub-pixel 234 is formed of a quantum dot, then the white sub-pixel234 can be made by mixing a white quantum dot with a surface coatingagent and a solvent, coating and volatizing to remove the solvent or canalternatively be made by mixing a combination of a red quantum dot, agreen quantum dot, and a blue quantum dot with a surface coating agentand a solvent, coating and volatizing to remove the solvent.

Wherein, the blue quantum dot may comprises ZnCdS, CdSe/ZnS or nanometerSiN₄. The green quantum dot may comprise CdSe/ZnS or ZnSe:Cu²⁺. The redquantum dot may comprise CdSe/CdS/ZnS. The white quantum dot maycomprise a quantum dot of Groups II-VI, such as CdSe, Cds, CdTe, CdMnS,ZnSe, or ZnMnSe.

The surface coating agent may comprise a stearic acid, trioctylphosphineoxide, or poly(methyl methacrylate).

The solvent may comprise methanol, ethanol, water, chlorobenzene, orchloroform.

In the above-described process of using a quantum dot to form asub-pixel, the organic host material and the surface coating agentprovide a common effect that is to prevent aggregation and oxidizationof the quantum dot. Since a quantum dot is a nanometer particle, whichis a zero-dimensional material, and has great surface activity, it iseasy to aggregate so as to lead to oxidization and quenching offluorescence.

For at least one of the sub-pixels being formed of an organiclight-emitting material, if the red sub-pixel 231 is formed of anorganic light-emitting material, then the red sub-pixel 231 can be madeby mixing an organic host material with a red light emissive materialand a solvent, coating and volatizing to remove the solvent; if thegreen sub-pixel 232 is formed of an organic light-emitting material,then the green sub-pixel 232 can be made by mixing an organic hostmaterial with a green light emissive material and a solvent, coating andvolatizing to remove the solvent; if the blue sub-pixel 233 is formed ofan organic light-emitting material, then the blue sub-pixel 233 can bemade by mixing an organic host material with a blue light emissivematerial and a solvent, coating and volatizing to remove the solvent;and if the white sub-pixel 234 is formed of an organic light-emittingmaterial, then the white sub-pixel 234 can be made by mixing an organichost material with a red light emissive material, a green light emissivematerial, a blue light emissive material and a solvent, coating andvolatizing to remove the solvent.

Wherein, the organic host material may comprise TCTA(4,4′,4″-tri(carbazol-9-yl)-triphenylamine) or TRZ(2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine) and the solvent maycomprise methanol, ethanol, water, chlorobenzene, or chloroform.

The blue light emissive material may comprise9,10-di(beta-naphthyl)anthracene (ADN), which has a structural formulaas follows:

The green light emissive material may comprisetris(2-phenylpyridine)iridium (Ir(ppy)₃), which has a structural formulaas follows:

The red light emissive material may comprise4-(dicyanomethylene)-2-methyl-6-(4-di methylaminostyryl)-4H-pyran (DCM),which has a structural formula as follows:

In the OLED device of the present invention, the substrate 1 can be athin-film transistor (TFT) substrate. The substrate 1 and the packagecover plate 2 are formed of glass or a flexible material. At least oneof the substrate 1 and the package cover plate 2 is light-transmittable.Preferably, the substrate 1 and the package cover plate 2 are both madeof glass sheets. The substrate 1 and the package cover plate 2 arebonded together by means of the sealing enclosing resin 3 to preventinvasion of external moisture and oxygen so as to seal and protectinternal electronic components.

The anode 21, the hole transporting layer 22, the electron transportinglayer 24, and the cathode 25 are each formed through a vacuum thermalevaporation process so that no fine metal mask (FMM) is needed.Preferably, the electron transporting layer 24 is formed oftris-(8-hydroxyquinolinato)aluminum (Alq3) and the hole transportinglayer 22 is formed of poly(triphenylamine) (poly-TPD) orpoly(ethylenedioxythiophene) (PEDOT).

Referring to FIG. 3, which is a schematic plan view illustrating anarrangement of pixels of the OLED device according to the presentinvention. FIG. 4 is a schematic view illustrating an application of thearrangement of pixels shown in FIG. 3 in a display panel. As shown inFIG. 5, the red sub-pixel 231, the green sub-pixel 232, the bluesub-pixel 233, and the white sub-pixel 234 are each driven by a TFT(Thin-Film Transistor) 4. Each of the sub-pixels corresponds to one TFTin order to in order to control the emission of light from an area ofthe emissive layer that corresponds to the sub-pixel.

Referring to FIG. 6, which is a schematic plan view illustrating anotherarrangement of pixels of the OLED device according to the presentinvention. FIG. 7 is a schematic view illustrating an application of thearrangement of pixels shown in FIG. 6 in a display panel.

In summary, the present invention provides a method for manufacturing anOLED device, wherein each of sub-pixels of an emissive layer is formedthrough a solution film casting process and an anode, a holetransporting layer, an electron transporting layer, and a cathode areformed through vacuum thermal evaporation processes, so that the methodfor manufacturing the OLED device requires no use of a fine metal maskthereby making the manufacturing cost incurring with the manufacturingmethod low, the utilization rate of material high, and the yield rategood; and with at least one sub-pixel of the emissive layer being formedof a quantum dot and at least one sub-pixel being formed of an organiclight-emitting material, the manufacturing method according to thepresent invention, when compared with a manufacturing method where allsub-pixels are formed of quantum dots, has a relatively lowmanufacturing cost and, when compared with a manufacturing method whereall sub-pixels are formed of organic light-emitting materials, providesan OLED device having a better performance. An OLED device manufacturedwith the present invention combines the advantages of a QD-OLED and asolution-film-cast OLED so as to possesses excellent performance,allowing for application to flat panel displays, televisions, and otherfields of displaying.

Based on the description given above, those having ordinary skills ofthe art may easily contemplate various changes and modifications of thetechnical solution and technical ideas of the present invention and allthese changes and modifications are considered within the protectionscope of right for the present invention.

What is claimed is:
 1. A method for manufacturing an organiclight-emitting diode (OLED) device, comprising: (1) providing asubstrate and forming, in sequence, an anode and a hole transportinglayer on the substrate; (2) forming an emissive layer on the holetransporting layer through a solution film casting process, wherein theemissive layer comprises a red sub-pixel, a green sub-pixel, a bluesub-pixel, and a white sub-pixel, of which at least one sub-pixel isformed of a quantum dot and at least one sub-pixel is formed of anorganic light-emitting material; (3) forming, in sequence, an electrontransporting layer and a cathode on the emissive layer; and (4)providing a package cover plate, which is set above the cathode, whereinthe substrate and the package cover plate are bonded together by sealingenclosing resin to complete packaging of the OLED device; wherein theanode, the hole transporting layer, the electron transporting layer, andthe cathode are each formed through a vacuum thermal evaporation processand the electron transporting layer is formed oftris-(8-hydroxyquinolinato)aluminum and the hole transporting layer isformed of poly(triphenylamine) or poly(ethylenedioxythiophene).
 2. Themethod for manufacturing the OLED device as claimed in claim 1, whereinthe substrate comprises a thin-film transistor (TFT) substrate; thesubstrate and the package cover plate are formed of glass or a flexiblematerial; and at least one of the substrate and the package cover plateis light transmittable.
 3. The method for manufacturing the OLED deviceas claimed in claim 1, wherein in step (2), at least one of thesub-pixels is formed of a quantum dot and if the red sub-pixel is formedof a quantum dot, then the red sub-pixel is made by mixing an organichost material with a red quantum dot and a solvent, coating andvolatizing to remove the solvent; if the green sub-pixel is formed of aquantum dot, then the green sub-pixel is made by mixing an organic hostmaterial with a green quantum dot and a solvent, coating and volatizingto remove the solvent; if the blue sub-pixel is formed of a quantum dot,then the blue sub-pixel is made by mixing an organic host material witha blue quantum dot and a solvent, coating and volatizing to remove thesolvent; and if the white sub-pixel is formed of a quantum dot, then thewhite sub-pixel is made by mixing an organic host material with a whitequantum dot and a solvent, coating and volatizing to remove the solventor is alternatively made by mixing an organic host material with acombination of a red quantum dot, a green quantum dot, and a bluequantum dot and a solvent, coating and volatizing to remove the solvent;the blue quantum dot comprises ZnCdS, CdSe/ZnS or nanometer SiN₄, thegreen quantum dot comprising CdSe/ZnS or ZnSe:Cu²⁺, the red quantum dotcomprising CdSe/CdS/ZnS, the white quantum dot comprising CdSe, Cds,CdTe, CdMnS, ZnSe, or ZnMnSe; the organic host material comprises4,4′,4″-tri(carbazol-9-yl)-triphenylamine or2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine; and the solvent comprisesmethanol, ethanol, chlorobenzene, or chloroform.
 4. The method formanufacturing the OLED device as claimed in claim 1, wherein in step(2), at least one of the sub-pixels is formed of a quantum dot and ifthe red sub-pixel is formed of a quantum dot, then the red sub-pixel ismade by mixing a red quantum dot with a surface coating agent and asolvent, coating and volatizing to remove the solvent; if the greensub-pixel is formed of a quantum dot, then the green sub-pixel is madeby mixing a green quantum dot with a surface coating agent and asolvent, coating and volatizing to remove the solvent; if the bluesub-pixel is formed of a quantum dot, then the blue sub-pixel is made bymixing a blue quantum dot with a surface coating agent and a solvent,coating and volatizing to remove the solvent; and if the white sub-pixelis formed of a quantum dot, then the white sub-pixel is made by mixing awhite quantum dot with a surface coating agent and a solvent, coatingand volatizing to remove the solvent or is alternatively made by mixinga combination of a red quantum dot, a green quantum dot, and a bluequantum dot with a surface coating agent and a solvent, coating andvolatizing to remove the solvent; the surface coating agent comprisesstearic acid, trioctylphosphine oxide, or poly(methyl methacrylate); thesolvent comprises methanol, ethanol, water, chlorobenzene, orchloroform; and the blue quantum dot comprises ZnCdS, CdSe/ZnS ornanometer SiN₄, the green quantum dot comprising CdSe/ZnS or ZnSe:Cu²⁺,the red quantum dot comprising CdSe/CdS/ZnS, the white quantum dotcomprising CdSe, Cds, CdTe, CdMnS, ZnSe, or ZnMnSe.
 5. The method formanufacturing the OLED device as claimed in claim 1, wherein in step(2), the at least one of the sub-pixels being formed of a quantum dot isthat the blue sub-pixel is formed of a quantum dot.
 6. The method formanufacturing the OLED device as claimed in claim 1, wherein in step(2), at least one of the sub-pixels is formed of an organiclight-emitting material and if the red sub-pixel is formed of an organiclight-emitting material, then the red sub-pixel is made by mixing anorganic host material with a red light emissive material and a solvent,coating and volatizing to remove the solvent; if the green sub-pixel isformed of an organic light-emitting material, then the green sub-pixelis made by mixing an organic host material with a green light emissivematerial and a solvent, coating and volatizing to remove the solvent; ifthe blue sub-pixel is formed of an organic light-emitting material, thenthe blue sub-pixel is made by mixing an organic host material with ablue light emissive material and a solvent, coating and volatizing toremove the solvent; and if the white sub-pixel is formed of an organiclight-emitting material, then the white sub-pixel is made by mixing anorganic host material with a red light emissive material, a green lightemissive material, a blue light emissive material and a solvent, coatingand volatizing to remove the solvent; the blue light emissive layercomprises 9,10-di(beta-naphthyl)anthracene, the green light emissivelayer comprising tris(2-phenylpyridine)iridium, the red light emissivelayer comprising4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran; theorganic host material comprises4,4′,4″-tri(carbazol-9-yl)-triphenylamine or2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine; and the solvent comprisesmethanol, ethanol, chlorobenzene, or chloroform.
 7. The method formanufacturing the OLED device as claimed in claim 1, wherein in step(2), the at least one of the sub-pixels being formed of an organiclight-emitting material is that the red sub-pixel, the green sub-pixel,and the white sub-pixel are formed of organic light-emitting materials.8. An OLED device manufactured with the method claimed in claim 1,comprising a substrate, an anode formed on the substrate, a holetransporting layer formed on the anode, an emissive layer formed on thehole transporting layer, an electron transporting layer formed on theemissive layer, a cathode formed on the electron transporting layer, apackage cover plate arranged above the cathode, and sealing enclosingresin arranged between the substrate and the package cover plate to bondthe substrate and the package cover plate together, the emissive layercomprising a red sub-pixel, a green sub-pixel, a blue sub-pixel, and awhite sub-pixel, wherein each of the sub-pixels is formed through asolution film casting process and wherein at least one of the sub-pixelsis made of a quantum dot and at least one of the sub-pixels is made ofan organic light-emitting material.
 9. The OLED device as claimed inclaim 8, wherein the blue sub-pixel is formed of a quantum dot and thered sub-pixel, the green sub-pixel, and the white sub-pixel are formedof organic light-emitting materials.
 10. An OLED device manufacturedwith the method claimed in claim 1, comprising a substrate, an anodeformed on the substrate, a hole transporting layer formed on the anode,an emissive layer formed on the hole transporting layer, an electrontransporting layer formed on the emissive layer, a cathode formed on theelectron transporting layer, a package cover plate arranged above thecathode, and sealing enclosing resin arranged between the substrate andthe package cover plate to bond the substrate and the package coverplate together, the emissive layer comprising a red sub-pixel, a greensub-pixel, a blue sub-pixel, and a white sub-pixel, wherein each of thesub-pixels is formed through a solution film casting process and whereinat least one of the sub-pixels is made of a quantum dot and at least oneof the sub-pixels is made of an organic light-emitting material; whereinthe blue sub-pixel is formed of a quantum dot and the red sub-pixel, thegreen sub-pixel, and the white sub-pixel are formed of organiclight-emitting materials.